Liquid crystal display device and mother substrate

ABSTRACT

In a liquid crystal display device including a TFT substrate and a counter substrate, when an organic s passivation film is not formed in the TFT substrate, the distance between the TFT substrate and the counter substrate in the display area of a liquid crystal display panel is provided by a cylindrical spacer. Also, the distance in the area where pixels, scan lines, and image signal lines are not formed within the liquid crystal display panel is provided by the cylindrical spacer. In this case, it is necessary to form a mount. The layer structure of the mount is the same as that of the TFT substrate with which the cylindrical spacer in the display area comes into contact. This makes it possible to equalize the distance of the liquid crystal layer of the liquid crystal display panel without an increase in production cost, and to prevent uneven brightness or color.

CLAIM OF PRIORITY

The present application claims priority from Japanese Patent ApplicationJP 2011-131714 filed on Jun. 14, 2011, the content of which is herebyincorporated by reference into this application.

FIELD OF THE INVENTION

The present invention relates to a display device, and more particularlyto a display device that can equalize the distance between upper andlower substrates to prevent the degradation of the display quality suchas uneven brightness and color.

BACKGROUND OF THE INVENTION

A display device, for example, a liquid crystal display panel used for aliquid crystal display device, includes a TFT substrate, a countersubstrate facing the TFT substrate, and a liquid crystal sandwichedbetween the TFT substrate and the counter substrate. In the TFTsubstrate, pixels having pixel electrodes, thin film transistors (TFT)and the like are arranged in a matrix. In the counter substrate, colorfilters and the like are formed at locations corresponding to the pixelelectrodes of the TFT substrate. In this way, the liquid crystal displaydevice forms an image by controlling the transmittance of light of theliquid crystal molecules for each pixel.

Liquid crystal display devices are flat and lightweight and extensivelyused is growing in a variety of applications. Compact liquid crystaldisplay devices are widely used in electronic devices such as mobilephones and digital still cameras (DSC). The viewing anglecharacteristics are important for the liquid crystal display device. Theviewing angle characteristic is the phenomenon in which the brightnesschanges or the color changes between when the display is viewed from thefront and when the display is viewed from an oblique direction. Theviewing angle characteristics are excellent in the in-plane switching(IPS) mode in which liquid crystal molecules are moved by the electricfiled in the horizontal direction.

There are many different types of the IPS mode. For example, a commonelectrode is formed flat, on which a pixel electrode having a slit isprovided with an insulating film interposed therebetween, to rotateliquid crystal molecules by the electric field generated between thepixel electrode and the common electrode. This type can increase thelight transmittance and is becoming mainstream. There is a structure inwhich an organic passivation film is provided between the pixelelectrode and common electrode and the TFT substrate. However, in orderto simplify the manufacturing process, a structure in which the organicpassivation film is not provided is also becoming popular.

In the liquid crystal display device, the distance between the TFTsubstrate and the counter substrate, namely, the thickness of the liquidcrystal layer has a significant influence on the characteristics. Ingeneral, the liquid crystal display device has been configured such thatthe distance in the display area is maintained by a cylindrical spacer,and that the distance in a sealing portion is maintained by a glassfiber. In recent years, however, in order to reduce the width of theso-called frame of the liquid crystal display panel, the leaders of scanlines or image signal lines are formed on the lower side of the sealingportion by double metal layer technology. In this case, the glass fiberis hard, so that there is a risk that the scan line leaders or imagesignal line leaders will be destroyed in gap adjustment. In order toprevent this, JP-A No. 168878/2009 describes the use of a cylindricalspacer formed by a resin also in the sealing portion.

Further, JP-A No. 168878/2009 also describes a method for providing anorganic passivation film as a mount for the cylindrical spacer in thesealing portion or in the vicinity thereof, in order to adjust thedistance between the TFT substrate and the counter substrate in thedisplay area.

In the third embodiment of JP-A No. 168878/2009 there is described aliquid crystal display device in which the organic passivation film isnot present. Also in this case, the distance between the TFT substrateand the counter substrate in the sealing portion is provided by thecylindrical spacer without using the glass fiber. Further, there is alsoproposed a structure for forming cylindrical spacers both inside andoutside the sealing portion. In JP-A No. 168878/2009, however, there isno description of a method for providing the distance by the cylindricalspacers in the display area and in the vicinity of the sealing portionwhen the organic passivation film is not used.

SUMMARY OF THE INVENTION

In the display device, for example, in the liquid crystal displaydevice, a driving circuit is directly formed into the liquid crystaldisplay panel in order to reduce the overall size of the liquid crystaldisplay device and reduce the number of leaders of lines. In this case,when the driving circuit is formed by poly silicon, the circuitcharacteristics are improved. However, when the TFT in the pixel area isformed by a-Si, the process is complicated. On the other hand, thecircuit size of the scan line driving circuit is smaller than that ofthe image signal line driving circuit, so that the scan line drivingcircuit can be formed by a-Si. For this reason, only the scan linedriving circuit is directly formed by a-Si into the liquid crystaldisplay panel and the image signal line driving circuit is formed by anIC driver. In such a structure, if the glass fiber is used for gapadjustment in the sealing portion, there is a risk that the scan linedriving circuit will be destroyed. Thus, it is necessary to use thecylindrical spacer formed by a resin.

Further, when the organic passivation film is used as described in thebackground of the invention, the organic passivation film also serves asa flattening film. When the organic passivation film is not used, thedistance between the TFT substrate and the counter substrate varies indifferent locations of the liquid crystal display panel. In this case,even if the cylindrical spacer is used, it is difficult to maintain thedistance between the TFT substrate and the counter substrate to beconstant.

It would be desirable to provide a liquid crystal display device inwhich the distance between the TFT substrate and the counter substratedoes not vary, so that uneven brightness, uneven color, or otherimperfections are not likely to occur in the liquid crystal displaypanel without using the inorganic passivation film that serves as aflattening film.

The present invention overcomes the above problems by means of thefollowing steps. A liquid crystal display device has a liquid crystaldisplay panel including a TFT substrate and a counter substrate facingthe TFT substrate through a sealing material, with a liquid crystalsandwiched between the TFT substrate and the counter substrate. Adisplay area where pixels are formed is provided inside the sealingmaterial of the TFT substrate. Then, an area where scan lines or imagesignal lines are formed as well as an area where the scan lines andimage signal lines are not formed are provided on the outside of thedisplay area inside the sealing material of the TFT substrate. Aflattening film formed of an organic film is not present in the displayarea. A cylindrical spacer is formed in the display area to provide thedistance between the TFT substrate and the counter substrate. Inside thesealing material and outside the display area, a layer structure, whichis the same as the layer formed in the TFT substrate with which thecylindrical spacer comes into contact, is formed in the display area.The metal layer of the layer structure formed on the outside of thedisplay area is floating.

Other key aspects of the present invention are as follows. A displaydevice has a first substrate and a second substrate facing the firstsubstrate through a sealing material. A display area where pixels areformed is provided inside the sealing material of the first substrate.Then, an area where a line or driving circuit is formed as well as anarea where the line and driving circuit are not formed are provided onthe outside of the display area inside the sealing material of the firstsubstrate. A flattening film formed by an organic film is not present inthe display area. Inside the sealing material and outside the displayarea, a cylindrical spacer is formed in the display area to provide thedistance between the first and second substrates. A mount is formed forthe cylindrical spacer provided in the area where the line and thedriving circuit are not present. The mount has the same layer structureas the layer formed corresponding to the cylindrical spacer in thedisplay area.

According to the present invention, it is possible to equalize thedistance between the TFT substrate and the counter substrate in theliquid crystal display panel. Thus, it is possible to prevent uneven gapof the liquid crystal display. In other words, it is possible to preventuneven brightness and color due to the variation of the distance betweenthe TFT substrate and the counter substrate. The mount, which is afeature of the present invention, can be formed when the display area ofthe liquid crystal display panel is formed. Thus, the number of steps ofthe manufacturing process is not increased. As a result, it is possibleto prevent the uneven brightness and color in the liquid crystal displaydevice without an increase in the production cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a TFT substrate of a liquid crystal displaypanel according to the present invention;

FIG. 2 is a plan view of the liquid crystal display panel according tothe present invention;

FIG. 3 is a cross-sectional view of the display area of the liquidcrystal display panel according to the present invention;

FIG. 4 shows a cross-sectional view of the display area in the liquidcrystal display device, and a cross-sectional view of the area wherelines are not present inside a sealing material;

FIG. 5 shows a cross-sectional view of the display area in the liquidcrystal display device according to the present invention, and across-sectional view of the area where lines are not present inside thesealing material;

FIG. 6 is a cross-sectional view of the sealing portion of the liquidcrystal display device according to the present invention;

FIG. 7 is a plan view of a mother substrate according to the presentinvention;

FIG. 8 shows a cross-sectional view of the display area in the mothersubstrate, and a cross-sectional view of a liquid crystal cell on theoutside of the sealing material;

FIG. 9 shows a cross-sectional view of the display area in the mothersubstrate, and a cross-sectional view of a liquid crystal cell on theoutside of the sealing material in which a mount is used;

FIG. 10 shows a cross-sectional view of the display area in the mothersubstrate, and a cross-sectional view of a liquid crystal cell on theoutside of the sealing material, in which a cylindrical spacer is formedon a back matrix and overcoat film and a mount is used as well;

FIG. 11 shows cross-sectional views of the liquid crystal display devicewhen the cylindrical spacer is provided above the TFT in the displayarea; and

FIG. 12 is a cross-sectional view of the liquid crystal display devicewhen the cylindrical spacer is provided above the TFT in the sealingportion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described in detail withreference to embodiments.

First Embodiment

FIG. 1 is a plan view of a TFT substrate 100 according to the presentinvention. In FIG. 1, scan lines 10 extend in the horizontal directionand are arranged in the vertical direction in the display area. A scanline driving circuit 12 is formed on the left side of the TFT substrate100. The scan lines 10 extend in the horizontal direction from the scanline driving circuit 12. Scan line driving circuit leaders 11 are formedin the scan line driving circuit to fetch signals from the outside. InFIG. 1, image signal lines 20 extend in the vertical direction and arearranged in the horizontal direction. Then, image signal line leaders 21extend from the image signal lines 20 to an IC driver 40.

The peripheral area between the dashed lines and the end portion shownin FIG. 1 is a sealing portion 50. In FIG. 1, a mount 140 for acylindrical spacer 150 formed in a counter substrate 200, not shown, isformed in the area where the lines are not present. In FIG. 1, thiscorresponds to the area where the image signal line 20 and the scan line10 are not provided inside the sealing portion 50, as well as the areawhere the image signal line leader 21 and the scan line driving circuitleader 11 are not provided on the outside of the sealing portion 50. InFIG. 1, two mounts 140 are formed inside the sealing portion 50, and twogroups of four mounts 140 are formed in two places on the outside of thesealing portion 50. However, this is only an example, and in generalmore of the mounts 140 are formed inside and outside the sealing portion50. Although not shown in FIG. 1, the mounts 140 are also formed in thedisplay area at a predetermined pitch. In general, the cylindricalspacer 150 formed inside the display area is smaller than thecylindrical spacer 150 formed outside the display area. Thus, the mount140 for the cylindrical spacer 150 formed inside the display area isalso small. However, the pitch, the size, and the like of the mount 140vary according to the needs of each product.

FIG. 2 shows the state in which the counter substrate 200 is attachedthrough the sealing material 50 with respect to FIG. 1. The inside ofthe sealing portion 50 is not shown except for the mounts 140. In FIG.2, the counter substrate 200 is not present in a terminal portion 120.Thus, the structure shown in FIG. 2 is the same as the structure shownin FIG. 1. In FIG. 2, the cylindrical spacer 150, not shown, is presentin the mount 140 within the sealing portion 50. However, the cylindricalspacer 150 is not present in each of the mounts 140 in the terminalportion 120. This is because the cylindrical spacer 150 is removed atthe same time when the area corresponding to the terminal portion of thecounter substrate 200 is removed.

FIG. 3 is a cross-sectional view of the display area of an IPS to whichthe present invention is applied. In FIG. 3, a gate electrode 101 isformed on the TFT substrate 100 formed from glass. For example, thestructure of the gate electrode 101 is such that MoCr is formed on anAlNd alloy. Then, a gate insulating film 102 is formed by sputtering SiNonto the gate electrode 101.

A semiconductor layer 103 is formed on the gate insulating film 102above the gate electrode 101. An a-Si film is formed by CVD as thesemiconductor layer 103. There are a drain electrode 104 and a sourceelectrode 105 formed facing each other on the semiconductor layer 103.The drain electrode 104 and the source electrode 105 are formed by MoCrat the same time. A channel layer is formed between the drain electrode104 and the source electrode 105 in the TFT. Note that an n+Si layer,not shown, is formed between the semiconductor layer 103 and the drainelectrode 104 or the source electrode 105 to obtain an ohmic contact.

In FIG. 3, the drain electrode 104 or the source electrode 105 isformed, and then a pixel electrode 106 is formed flat by ITO. A portionof the pixel electrode 106 overlaps the source electrode 105 to providean electrical contact between the pixel electrode 106 and the sourceelectrode 105. Then, an inorganic passivation film 107 is formed so asto cover the drain electrode 104, the source electrode 105, the pixelelectrode 106 and the like. The passivation film 107 is formed by CVD ofSiN. The original purpose of the passivation film 107 is to protect theTFT. In FIG. 3, however, the passivation film 107 also serves as aninsulating film between the common electrode 108 and the pixel electrode106.

A comb-like common electrode 108 is formed on the passivation film 107.An oriented film, not shown, is formed on the common electrode 108.Then, the liquid crystal layer is present on the oriented film. In FIG.3, T represents the area where the TFT is formed, S represents the areawhere the source electrode 105 is formed, P represents the area wherethe pixel electrode 106 is formed, and D represents the area where theimage signal line 20 is formed, respectively.

In FIG. 3, a color filter 201 and a black matrix 202 are formed on thecounter substrate 200, on which an overcoat film 203 is formed. Thecylindrical spacer 150 is formed on the overcoat film 203. The blackmatrix 202 formed on the counter substrate 200 covers the cylindricalspacer 150, and the image signal line 20 and the like formed on thecounter substrate 200. Note that the oriented film on the overcoat film203 is not shown in the figure.

As shown in FIG. 3, the distance between the TFT substrate 100 and thecounter substrate 200 is maintained by the cylindrical spacer 150. InFIG. 3, in the portion with which the cylindrical spacer 150 comes intocontact, the gate insulating film 102, the image signal line 20, theinorganic passivation film 107, and the common electrode 108 arepresent. Thus, these films have the same function as the mount.

FIG. 4 shows cross-sectional views in which the cylindrical spacer 150is formed in the area where the lines and the like are not providedinside the sealing portion 50. The left side of FIG. 4 is the same asFIG. 3 and the description thereof will be omitted. As shown in FIG. 4,also inside the sealing portion 50, there is only the gate insulatingfilm 102 present in the TFT substrate 100 in the area where the linesand the like are not provided. Thus, the end of the cylindrical spacer150 is floating with a gap g1 between the TFT substrate 100 and the gateinsulating film 102. For this reason, even if the cylindrical spacer 150is formed, it is difficult to properly form a gap between the TFTsubstrate 100 and the counter substrate 200.

FIG. 5 shows cross-sectional views of the portion of the cylindricalspacer 150 inside the sealing portion 50. In FIG. 5, the mount 140 isformed in the portion of the TFT substrate 100 facing the cylindricalspacer 150 in the area where the lines are not provided. The mount 140has the same film structure as the portion where the cylindrical spacer150 is formed in the display area. In FIG. 5, the mount 140 is formed onthe gate insulating film 102. The mount 140 is formed by a metal layer110 which is the same layer as the image signal line, the inorganicpassivation film 107, and the ITO 108 which is the same layer as thecommon electrode. The metal layer 110 and the ITO 108 of the layersforming the mount 140 are conductive films. These conductive layers arefloating.

FIG. 6 is a cross-sectional view showing the state in which the distancebetween the TFT substrate 100 and the counter substrate 200 in thesealing portion 50 is provided by the cylindrical spacer 150, when theTFT for the scan line driving circuit 12 is formed in the sealingportion 50. In FIG. 6, the cylindrical spacer 150 is formed over the TFTsubstrate 100 in the area of the same film structure as that shown inFIG. 3. In FIG. 6, when the black matrix 202 and the overcoat film 203are formed on the counter substrate 200 in which the cylindrical spacer150 is formed, there is a possibility that the adhesion of the sealingmaterial 50 is reduced. In this case, the black matrix 202 and theovercoat film 203 may be formed like islands only in the area where thecylindrical spacer 150 is formed. In FIG. 6, the structure with only oneTFT is disclosed. However, a plurality of TFTs are formed in the scanline driving circuit and various lines are provided to connect the TFTs,but there is no particular limitations with respect to these structures.

As described above, according to this embodiment, it is possible toproperly provide the distance between the TFT substrate 100 and thecounter substrate 200 both in the display area and the surrounding area,at least inside the sealing portion 50. Thus, it is possible to preventthe uneven brightness, uneven color, or other imperfections due to theuneven gap and the like.

Second Embodiment

In order to increase the productivity of liquid crystal display panels,a large number of liquid crystal display panels (liquid crystal cells)are formed in a mother substrate 1000 to simultaneously form a largenumber of liquid crystal cells. Thus, if the distance between the TFTsubstrate 100 and the counter substrate 200 in each liquid crystal cellis not properly provided in the state of the mother substrate 1000, thiswill appear as uneven gap of the product.

FIG. 7 is a schematic plan view of the structure to solve this problem.FIG. 7 shows the mother substrate 1000 in which a large number of liquidcrystal cells are formed. The mother substrate 1000 is formed by bondinga mother TFT substrate in which a large number of TFT substrates 100 areformed, and a mother counter substrate in which a large number ofcounter substrates 200 are formed, by a mother substrate sealingmaterial 500 as well as the sealing material 50 formed in each liquidcrystal display panel.

In FIG. 7, twelve liquid crystal cells are formed in one mothersubstrate 1000. The dashed line of each liquid crystal cell indicatesthe boundary between the display area and a terminal portion 60. In thestate shown in FIG. 7, the counter substrate 200 still faces the portionopposite to the terminal portion 60. Thus, in order to maintain thedistance between the TFT substrate 100 and the counter substrate 200 tobe a predetermined distance, it is necessary to provide the cylindricalspacer 150 formed in the counter substrate 200 and the mount 140 formedin the TFT substrate 100 also in the terminal portion 60. Note that theimage signal line leaders 21 are provided in the terminal portion 60 ofeach liquid crystal cell shown in FIG. 7. Further, the positions of theIC drivers are indicated by the dashed lines. However, the IC driversare not yet mounted in the state of the mother substrate.

In FIG. 7, also in the area where the individual liquid crystal cellsare not formed, the mount 140 for the cylindrical spacer 150 is formedin the TFT substrate 100, and the cylindrical spacer 150 (not shown) isformed in the counter substrate 200. In this way, it is possible toequalize the distance between the TFT substrate 100 and the countersubstrate 200 in the entire mother substrate 1000. As a result, thedistance can be fixed in each liquid crystal cell. In FIG. 7, the mothersubstrate sealing material 500 is formed around the entire perimeter ofthe mother substrate 1000 to make the inside of the mother substrate1000 airtight. The reason why the inside of the mother substrate 1000 ismade airtight is that the outside of the substrate may be ground toreduce the thickness of the TFT substrate 100 or the counter substrate200 after the mother substrate is formed.

FIG. 8 is a cross-sectional view in which the cylindrical spacer 150 isformed in the area where the liquid crystal cells are not provided shownin FIG. 7. In FIG. 8, there is no film formed on the outside of theliquid crystal cell in the counter substrate 200, and only the gateinsulating film 102 is formed in the TFT substrate 100. In such astructure, when the cylindrical spacer 150 is formed in the countersubstrate 200, a gap g2 is formed. This does not mean that the distancebetween the TFT substrate 100 and the counter substrate 200 is providedby the cylindrical spacer 150. In other words, in the state shown inFIG. 8, the TFT substrate 100 or the counter substrate 200 is deformedwhen the pressure is applied from the outside, so that the distancebetween the counter substrate 200 and the TFT substrate 100 may not bemaintained constant.

FIG. 9 shows the state in which the mount 140 is formed in the TFTsubstrate 100 with respect to the cylindrical spacer 150 formed at theposition similar to that shown in FIG. 8. The mount 140 is formed by thefollowing three layers: the metal layer 110 that is the same as theimage signal line layer formed on the gate insulating film 102; theinorganic passivation film 107; and the ITO 108 that is the same as thecommon electrode layer. In this case, the metal layer 110 and the ITO108, which are conductive films, are floating. This film structure isthe same as the film structure of the portion where the cylindricalspacer 150 in the display area faces the TFT substrate 100. However, inthis case also, compared to the display area, since the black matrix 202and the overcoat film 203 are not formed, a gap g3 is formed between thecylindrical spacer 150 and the mount 140. Thus, the distance may not becompletely equal to the distance in the display area.

FIG. 10 shows the state in which the mount 140 is formed in the TFTsubstrate 100 with respect to the cylindrical spacer 150 at the positionsimilar to that shown in FIG. 8. The structure of the mount 140 is thesame as the structure shown in FIG. 9. FIG. 10 is different from FIG. 9in that the cylindrical spacer mount 140, which is formed from the blackmatrix 202 and the overcoat film 203, is also provided in the countersubstrate 200. The cylindrical spacer 150 is formed on the laminatedfilm with the same structure as the black matrix 202 and the overcoatfilm 203, which are formed on the counter substrate 200 in the displayarea shown in FIG. 10.

Thus, with the structure shown in FIG. 10, it is possible to completelyequalize the distance between the counter substrate 200 and the TFTsubstrate 100 in the area where the display area, and the terminalportion 60 and the liquid crystal cell, which are shown in FIG. 7, arenot formed. Thus, the uneven gap does not occur also in the area where aliquid crystal layer 300 exists in the liquid crystal cell.

As described above, according to this embodiment, it is possible tomaintain the distance between the TFT substrate 100 and the countersubstrate 200 to be constant in the entire mother substrate 1000.

Third Embodiment

A third embodiment is an example in which the cylindrical spacer 150 isformed on the TFT to maintain the distance between the TFT substrate 100and the counter substrate 200 in the display area. In FIG. 11, in thedisplay area, the cylindrical spacer 150 formed in the counter substrate200 comes into contact above the TFT formed in the TFT substrate 100. Inthis case, the structure of the mount 140 within the sealing portion 50shown in FIG. 1, has the gate electrode 101, the gate insulating film102, the a-Si film 103, the source-drain layer 105, the inorganicpassivation film 107, and the ITO forming the common electrode 108, inthis order from the bottom in the counter substrate 200. Thus, the mount140 shown in the right side of FIG. 11 has the same layer structure asthat of the mount 140 shown in FIG. 1. Here, in the mount 140 shown inthe right side of FIG. 11, the gate electrode 101, the source-drainelectrode 105, and the ITO 108 are conductive films. These conductivefilms are floating.

FIG. 12 is a cross-sectional view of the sealing portion 50 according tothis embodiment. In FIG. 12, the cylindrical spacer 150 is presentwithin the sealing material 50. The cylindrical spacer 150 comes intocontact with an oriented film formed on the common electrode 108 formedin the TFT substrate 100, above the TFT constituting the scan linedriving circuit 12. In other words, the layer structure of the portionof the TFT substrate 100 with which the cylindrical spacer 150 comesinto contact in FIG. 12 is the same both in the display area and in thesealing portion 50.

Although not shown, the layer structure of the mounts 140 shown in FIG.7, which are formed in the terminal portion 60 of the liquid crystalcell and in the area where the liquid crystal cell is not formed, isalso the same as the layer structure shown in FIG. 11 or 12. In otherwords, the layer structure has the gate electrode 101, the gateinsulating film 102, the a-Si film 103, the source-drain layer 105, theinorganic passivation film 107, and the ITO forming the common electrode108. Then, the gate electrode 101, the source-drain electrodes 104, 105,and the ITO 108 are conductive films. These conductive films arefloating.

As described above, according to the present invention, the mount 140for the cylindrical spacer 150 formed in the area other than the displayarea, has the same layer structure as that of the mount 140 in theportion of the TFT substrate 100 with which the cylindrical spacer 150comes into contact in the display area. Thus, it is possible to equalizethe distance between the display area and the other area of the liquidcrystal display panel, preventing the occurrence of uneven brightnessand color, or other imperfections.

According to the embodiments of the present invention, the cylindricalspacer 150 comes into contact with the TFT substrate 100 above the imagesignal line 20 or the TFT. However, the present invention is not limitedto this structure. When the cylindrical spacer 150 comes into contactwith the TFT substrate 100 in the area other than the display area, itis possible to form the mount 140 with the same layer structure as thatin the display area, as the mount 140 with which the cylindrical spacer150 comes into contact in the area other than the display area of theliquid crystal display panel.

Further, the mount 140 according to the present invention can be formedat the time of the formation process of the display area of the TFTsubstrate 100 or the formation process of the display area of thecounter substrate 200. Thus, the production cost will not increase.

Further, in each of the embodiments of the present invention, the mountprovided in the area where the terminal portion and the liquid crystalcell are not provided has the same structure as the mount provided inthe display area. However, the present invention is not limited thereto.For example, it is also possible to use the metal layer that is the sameas the scan line layer, instead of using the metal layer that is thesame as the image signal line layer used as the mount, by taking intoaccount the film thickness of each layer and the likelihood of the gapformation. Further, it is possible to use the ITO that is the same asthe pixel electrode layer, instead of using the ITO that is the same asthe common electrode layer. In addition, it is possible to use the colorfilter layer as a base mount for the cylindrical spacer, instead of theblack matrix or the cover coat layer. Further, although the conductivelayer of the mount is floating, the conductive layer can be connected tothe other conductive layer to apply a certain potential to the whole ora portion of the conductive layer of the mount.

Further, according to the embodiments of the present invention, the scanline driving circuit is formed by a-Si. However, it will be understoodthat a variety of structures can be used without departing from thespirit and scope of the present invention. For example, the pixels andthe scan line driving circuit is formed by poly silicon, or the scanline driving circuit is not formed under the seal.

Although the above description exemplifies the IPS-type liquid crystaldisplay device, the present invention is not limited to this example.The present invention can also be applied to liquid crystal displaydevices of other types such as TN and VA without having the organicpassivation film that is also used as the flattening film in the liquidcrystal display panel. Further, the present invention can be applied notonly to liquid crystal display devices, but also to display devices inwhich two glass substrates corresponding to the TFT substrate and thecounter substrate are maintained at a predetermined distance including,for example, organic EL display devices and MEMS display devices thatcontrols the transmittance of light by a mechanical driving mechanism.

1. A liquid crystal display device comprising a liquid crystal displaypanel including a TFT substrate and a counter substrate facing the TFTsubstrate through a sealing material, with a liquid crystal sandwichedbetween the TFT substrate and the counter substrate, wherein a displayarea where pixels are formed is provided inside the sealing material ofthe TFT substrate, wherein an area where scan lines or image signallines are formed as well as an area where the scan lines and the imagesignal lines are not formed, are provided on the outside of the displayarea inside the sealing material of the TFT substrate, wherein aflattening film formed of an organic film is not present in the displayarea, wherein a cylindrical spacer is formed within the display area toprovide the distance between the TFT substrate and the countersubstrate, wherein inside the sealing material and outside the displayarea, a layer structure is formed in the area where the scan line andimage signal line are not present, wherein the layer structure is thesame as the layer formed in the TFT substrate with which the cylindricalspacer comes into contact in the display area, and wherein the metallayer of the layer structure formed on the outside of the display areais floating.
 2. The liquid crystal display device according to claim 1,wherein a scan line driving circuit is formed in the area where thesealing material is formed in the TFT substrate, wherein a cylindricalspacer is formed in the counter substrate above the scan line drivingcircuit, and wherein the layer of the TFT substrate with which thecylindrical spacer formed above the scan line driving circuit comes intocontact, has the same layer structure as the layer of the TFT substratein the area with which the cylindrical spacer comes into contact in thedisplay area.
 3. The liquid crystal display device according to claim 2,wherein the TFT substrate is larger than the counter substrate, whereina terminal portion is formed in the area where the TFT substrate doesnot overlap the counter substrate, wherein an image signal line leaderconnected to the image signal line, and a scan line driving circuitleader connected to the scan line driving circuit are formed in theterminal portion, wherein a cylindrical spacer mount is formed in thearea where the image signal line leader and the scan line drivingcircuit leader are not formed, and wherein the cylindrical spacer mountformed in the terminal portion has the same layer structure as the layerformed in the TFT substrate with which the cylindrical spacer formed inthe display area comes into contact.
 4. The liquid crystal displaydevice according to claim 2, wherein the cylindrical spacer formed inthe counter substrate in the area where the sealing material is formed,is formed in the area where the black matrix and the overcoat film areformed like islands.
 5. A mother substrate comprising a mother TFTsubstrate and a mother counter substrate, wherein a plurality of liquidcrystal display panels are formed in the mother TFT substrate, whereinthe distance between the TFT substrate and the counter substrate isprovided by a cylindrical spacer in the display area within the liquidcrystal display panel, wherein the distance between the mother countersubstrate and the mother TFT substrate is provided by a cylindricalspacer in the area where the liquid crystal display panel is not formed,wherein the end of the cylindrical spacer in the area where the liquidcrystal display panel is not present comes into contact with a mountformed in the mother TFT substrate, wherein the mount has the same layerstructure as the layer structure formed on the side of the TFT substratewhere the cylindrical spacer is formed in the liquid crystal displaypanel, and wherein the conductive film in the layer structure isfloating.
 6. The mother substrate according to claim 5, wherein themount with which the end of the cylindrical spacer in the area where theliquid crystal display panel is not present comes into contact is formedlike an island.
 7. A liquid crystal display device comprising a firstsubstrate and a second substrate facing the first substrate through asealing material, wherein a display area where pixels are formed isprovided inside the sealing material of the first substrate, wherein anarea where a line or a driving circuit is formed as well as an areawhere the line and the driving circuit are not formed are provided onthe outside of the display area inside the sealing material of the firstsubstrate, wherein a flattening film formed by an organic film is notpresent in the display area, wherein a cylindrical spacer is formedwithin the display area to provide the distance between the first andsecond substrates, wherein inside the sealing material and outside thedisplay area, a mount is formed for the cylindrical spacer provided inthe area where the line and the driving circuit are not present, andwherein the mount has the same layer structure as the layer formedcorresponding to the cylindrical spacer in the display area.
 8. Theliquid crystal display device according to claim 7, wherein a mount isformed for the cylindrical spacer provided in the area where the line orthe driving circuit is formed on the outside of the display area, andwherein the mount has the same layer structure as the layer formedcorresponding to the cylindrical spacer in the display area.
 9. Theliquid crystal display device according to claim 7, wherein inside thesealing material and outside the display area, the metal layer of themount formed for the cylindrical spacer provided in the area where theline and the driving circuit are not present, is floating.